摘要：微型流式细胞仪综合了流式细胞术和微流体的优势,已成为生物医学、临床应用领域低成本的细胞检测、分析方法。微型流式细胞仪的一个新兴应用是快速检测低浓度的细胞或粒子。基于一种集成了片内光束整形和微流体通道的微加工芯片,自主设计搭建了一种微型流式细胞仪。利用该微型流式细胞仪进行了实时微珠计数实验,实验结果表明微珠通量与样品的体积流量、样品浓度之间的线性相关系数均大于0.99。高线性结果验证了这种微型流式细胞仪的高精度计数功能,使其成为低浓度应用的理想选择,如检测食物或水中的病原体。

摘要：GaAs-based planar Gunn diodes with A1GaAs hot electron injector have been successfully developed to be used as a local oscillator of 76 GHz in monolithic millimeter-wave integrated circuits. We designed two kinds of structure diode, one has a fixed distance between the anode and cathode, but has variational cathode area, the other has a fixed cathode area, but has different distances between two electrodes. The fabrication of Gunn diode is performed in accordance with the order of operations： cathode defining, mesa etching, anode defining, isolation, passivation, via hole and electroplating. A peak current density of 29.5 kA/cm^2 is obtained. And the charavteristics of negative differential resistance and the asymmetry of the current-voltage curve due to the A1GaAs hot electron injector are discussed in detail. It is demonstrated that the smaller size of active area corresponds to the smaller current, and the shorter distance between anode and cathode also corresponds to the lower threshold voltage and higher peak current, and hot electron injector can effectively enhance the radio frequency conversion efficiency and output power.